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2 Sheets-Sheet 1'; y

s; D. TILLMAN.

Making Iron Pavements.

Patented March 27, 1860.

2 Sheets-Sheet 2.,

s. DQTILLMAN.

' Making Iron Pavements.

No. 27,658. Patented March`27, 1860.

"EEE STATE@ Prlllhl SAMUEL D. LILLMAN, OF NEWT YORK, N. Y.

MODE OF IJIAKNG PAVEMENTS.

Specification of Letters ratent No. 27,658, dated March 27, 1860.

To all whom it may concern:

Be it known that SAMUEL D. Tinmmn, of the city and State of New York, have invented a neiv and Improved Mode of Paving Streets or Roads; and l do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, illustrating the same.

The object of my invention is to provide streets and public highways with a solid safe and economical pavement, and the mode by which this object is accomplished is by using blocks or plates of iron of peculiarl construction which shall present to the wheels of a common vehicle a smooth path, give the horse attached to suoli vehicle a sure foot-hold and the best means of exerting his greatest power of traction and also make ample provision for drainage.

Figure l, of the annexed drawings represents the upper side or exposed portion of two plates connected side by side having elevations and depressions regularly alternating with each other transversely and longitudinally. F Q, is the under side of the same plates. Fig. 3, a longitudinal section of the plates at their line of junction side by side. Fig. 4, a transverse section of same plates at their line of junction by a similar mode end to end. Fig. T, a view of similar plates of large size laid on a foundation of cross-ties. Fig. 8 is a view of a tlanch added underneath large plates. Fig. 6 is a perspective view of indented platesso arranged as to form a channel for drainage. Fig. 5 is view of an indented plate having flanches on its sides so as to form a hollow block.

Like letters refer to like parts in each figure.

It seems necessary first to notice the defects in the common modes of pavement in order to show more clearly the manner in which these defects are remedied by my improvement. rThe Cobble stone pavement is defective in two respects; first, in its liability to be moved by the action of heat and cold; second in its roughness. A four wheeled vehicle passing over it is constantly receiving a succession of double shocks or concussions by means of its forward wheels striking a series of projections; these are repeated by the hind wheels following in the the same line. The/force of these concussions are measured by the weight moved and its velocity. Allowing cobble stones to be six inches apart, each wheel would strike 10,560 stones in one mile and number of concussione received by the vehicle in that distance would be 42,240. An omnibus moving over twelve miles of such road would receive the enormous number of 506,880 concussions. These concussions are communicated in a greater or less degree to the horses attached to it. The daily wear of both horses and carriages by means of this pavement need not be commented on. remedy was tried by substituting square smoothfaced stones placed with their edges diagonal to the line of the street. It was found that although a smooth path, comparatively, was obtained for the wheels there was in fact no sure foothold for the horse, as the stones became smoother from wear this objection became still more apparent. A later improvement was the use of smooth faced stones about six inches in diameter laid square with the street. The spaces between the stones prevented the foot of a horse from slipping more than six inches without being arrested but the wheels of carriages are pressed into these spaces and by that action the edges of these stones are gradually rounded.

The objections to inacadamized roads and roads made partly of iron and partly of sand are the want of solidity of surface and the constant presence of dust or dirt. The greatest advance in the art of locomotion was at the introduction of a perfectly smooth and solid track of iron just wide enough for the wheel which was held in its place by means of a ilanch at its periphery. This simple improvement is the main feature in that grand invention. The iron railway, which cannot be superceded where all the carriages in use may be moved in one continuous line. lt cannot however, by any increase in the number of rails, be adapted to general use on highways where carriages are moving in every direction.

The obj ect of my improvement is to adapt the best feature of the railway to the common road and unite the best wheel way with the best horse way, first, by presenting a series of smooth solid surfaces for the path of the wheel in any direction, these surfaces being as extended as possible while fulfilling other conditions, `in order to spread the pressure of the wneel over a large area thereby diminishing the wear; such surfaces formthe grade of the road and may be termed grade surfaces; second, by making between such surfaces, indentations or depressions running crosswise of the road or at right angles to the general line of traction, thereby giving the horse moving over it, the opportunity of finding at short intervals the surest and best foothold; these indentations or depressions being in width and length, sufficient to admit either of the calks of the common horse shoe, yet of such length as not to be equal to the width of the tire of a common wheel, and their sides should be substantially vertical; thus preventing the wheel from falling into the depressions, and avoiding shocks while the foothold of the horses is secured; third, by using a form of metal by means of these grade surfaces and indentations and the partitions b-etween them, which will secure the greatest power of resistance with a given amount of iron; fourth, by providing such pavement, when required, with perfect drainage by means of channels running obliquely across it yet bounded by right lines ruiming parallel with and perpendicular to the line of the road.

Two plates having grade-surfaces and corresponding indentations, regularly alternating with each other both lengthwise and crosswire are represented by Fig. l, a, o being the line of junction. The plates are in miniature, but the grade surfaces (g g g) and the indent-ations z' are about the size of those required for practical use. The width .of each indentation (m n) being a little more than that of the heel calk of a common horse shoe, and the length (la Z) slightly exceeding that of the toe-calk of such shoe yet not equal to the width of a common wheel tire it follows that a series of depressions are thus formed for the reception of the calks of a horse shoe which entirely exclude the common wheel, and allow it to roll smooth along from one grade surface to another or to two others on either side, without sinking below the line of the grade. It .is true that the indentations if made much longer than the width of the wheel would not, owing to its narrowness, permit the wheel to sink to an extent perceptible to the eye yet the wheel through that distance has not its usual perpendicular support and must be sustained by the edges of the adjoining grade surfaces. This occasions a wear to which other parts of the surface are not subject and eventually destroys the grade of the road. This evil is obviated by. my arrangement of grade surfaces, on some parts of which the wheel has a constant perpendicular support, or in other words the point of pressure and the axis of the wheel are always kept in the same vertical line. The horse in order to exert his greatest power requires not only a sure foothold but one that will not tend to turn his foot sidewise, the

indentations z' therefore run at right angles to the general line of traction. The

.tations may also b-e varied from one eighth to one half an inch. It being understood that their size depends on the length of the toe calk of the horse shoe and the width of the wheel tire in common use. A slight decrease in the length and increase in the width of the toe calk now used would not impair its strength or efficiency yet would allow the use of shorter indentations and thereby insuring more perfectly the edges of the grade surfaces from the wear caused by the pressure of the wheel.

The thickness of the plates (Fig. l) depend on their size they are made with cavities underneath the grade surfaces so that when the plates are upside down as seen in Fig. 2 the underside of the true indentations will appear as grade surfaces and the true grade surfaces as the bottom of the plate. The indentations above and below, are separated by partitions as seen in Fig. 3; these partitions, connected with the horizontal portions forniing the top and bottom of the plate, make a series of cells closed on all sides but one. Each cell having a closed side above alternates with one having a closed side below. The partitions may be as thick between the ends of the indentations (as seen in Fig. 4) as they are between the sides or even thicker if required. This cellular work gives great stiffness to the plate; a given amount of iron in this form will resist a greater lateral pressure than it would in the form of a plate bounded by two planes. I am aware that corrugated work has been made, and cell work where the cells are closed one side, or all on both, sides but I have never seen before, cells made having their ends closed alternately above and below.

The plates represented by Fig. 6 have indentations (i z' z') and grade surfaces (g g g) like those in Fig. l; they alternate transversely with each other, but longitudinally with the road they pass by or overlap each other; the indentations z' z') as well as grade surfaces (g g g)are thereby connected and thus form a channel or drain, running obliquely across the roadway, through which all water and other liquid is carried to the gutter. The plates as united at a I) Fig. 6 show how this channel is continued uninterruptedly from one to the other. The channels so formed, commence at the center or highest part of the street and may run on either side, obliquely forward or obliquely backward, to the gutter. If in moving forward on a street, its grade is slightly ascending these channels must run obliquely backward, if descending they must run obliquely forward. On very steep grades thc plates in Fig. l should be used, because the horse has on them a better chance of foothold, with the least slip, and there not as much necessity for drainage in the manner above set forth. lVhere streets cross each other, if plates are used alternating its indentations and grade surfaces regularly in both directions, the indcntations should be made in width equal to the length which is not increased and the grade surfaces made to correspond. This arrangement increases the liability to slip, but if the plates shown in Fig. 6 are used, the indentations are only widened to half their length, in other words the distance a 0 is made equal to n j), and the facility of passing over it crosswise or lengthwise is the same.

Oblique joints and channels have beforebeen made in stone roads but the channel here described is an oblique Zig-Zag; that is it is bounded by right lines. running longitudinally and transversely, thereby forming a series of projections, which enable the horse to obtain a square foot-hold. The plates (Fig. are made with a single plain surface underneath but they may have cavities nnderneath corresponding to the grade surfaces, it is not pretended however that such a form of plate has the strength of resistance to lateral pressure of those made in the form shown by Fig. l.

The plates Fig. G are designed also for cross walks and sidewalks in which case the oblique channels may commence on one side of the walk and terminate on the other. T he right lines bounding these rchannels give great security to the pedestrian against slipping forward, backward or sidewise. The water being conveyed away rapidly during a rain the raised surfaces even then afford a comparatively dry passage way.

The principle on which my pavement is constructed, being the formation of a continuous series of surfaces. on some of which the wheel may at all times press perpendicularly and roll without impediment; and the formation of indentations, alternating with such surfaces, each of which extends crosswise to the road suthciently to admit the toe piece of a horseshoe and yet exclude the wheel in common use it is evident that slight alteration of the contour of the indentations and grade surfaces will not alter the principle as set forth.

It is proper that some of the modifications should be noticed and explained. The corners of the indentations may be rounded and the sides slightly curved and it may be proved by experience that such modification may add to the durability of the road. lllhere the plates are laid on a solid foundation the bottom part of such indentations may be left oft' so as to form an opening through the plate instead of an indentation i ier-ely. The dotted lines g g .t x show the alte ations that may be made in form as seen in Fig. The longitudinal lines of the indentation may run slightly oblique, providing there is still room for the admission of the toe calli as set forth, but if made too oblique, as seen by dotted lines r, r, r, r, Fig. 5 the principle is violated because the toe calk cannot find an entrance. The indentations may be connected by channels lw. The pavement thus fully described may be laid down in plates or in the form of hollow blocks on a properly prepared foundation in the usual manner of doing such work. Fig. l represents the form when used as plates, c c being the lateral projections on one plate litting in to recesses e e (Fig. 3) in the adjoining' plate. A similar series of projections as seen in Fig. l may be made on the ends of these plates. These projections have the advantage of being entirely covered and protected from the action of the wheel. The plates may be made of any feasible length; those shown in Fig. 7 are supposed to be six feet long by three broad; they rest on cross ties (t) of wood, to which they are fastened by spikes (s) passing through an indentation as seen at s Fig. l far enough to bring the bent-head of the spike below the grade surface. Flanches are shown in Fig. S or any other approved form may be added underneath such plates for the purpose of strengthening them.

lVhen this pavement is put down in blocks, made hollow by casting a flanch around the sides of a plate and projecting downward, the general form of such block should be a square or parallelogram, and 'should be laid at right angles with the street, because the force of traction is generally pressing lengthwise with it, while the weight of the vehicle is, by the curve or arch of the street, causing a pressure crosswise to it.

Fig. 5 is a perspective view of the square block having flanches (f 7") projecting downward from its four sides and made thereby, what is called, a hollow block. rlhe sides may be plain or formed with lateral projections and recesses as seen in Fig. G, where the dotted lines represent a horizontal section of the flanch having projections and recesses alternating with and matched into those of an adjoining block, (see g z" .Fig 6).

lVhere the expense of covering an entire street with an iron pavement cannot be incurred this kind of pavement may be laid down in the center of the street of sufficient width for the passage of one, or of two vehieles side and side While the remainder of the street may be covered With the usual coble stone pavement. It may also be laid down in narrow strips, about one foot in Width in combination with other kinds of pavement, these strips being designed for the path of the Wheel, thereby forming a tram- Way. None of these arrangements however can be compared in eiiiciency to an entire solid pavement, covering the Whole street, of iron having grade surfaces and indentations, as above described, the introduction of which into general use the inventor believes would form a new era into the history of locomotion.

In constructing sidewalks on the plan set forth, brick or other suitable hard material may be substituted for iron.

Having thus fully set forth my invention what I claim as new, and for Which I ask f SAMUEL D. TILLMAN.

Witnesses FRANCIS I). SWEET,

S. L. H. WARD. 

